These studies are designed to determine the effects of chronic ethanol consumption on myocardial structure, biochemistry, and mechanical function. Previous work has suggested that long-term consumption of ethanol results in ultrastructural abnormalities (swelling of mitochondria, transverse tubules, and sarcoplasmic reticulum; disintegrated myofibrils; mitochondrial clumping) and biochemical abberations (depressed mitochondrial respiratory capacity and diminished myofibrillar ATPase activity). Proposed studies and work in progress will evaluate the mechanical and pump performance of isolated working hearts of rats that have consumed ethanol as 38% of their daily calories for periods up to 1 year. In addition, an assessment of sarcoplasmic reticulum calcium uptake and binding in alcoholic hearts will be made. The reversibility of cardiac structural, metabolic, and functional damage will also be examined. These studies are anticipated to yield information pertinent to the pathogenesis and management of alcoholic cardiomyopathy in patients.